There is a significant discussion occurring on Cruisers Forum about the interpretation of this rule.
Feedback included information from the USCG and the UK MCA. A Danish perspective is awaiting the opening of the offices on Tuesday.
The USCG references Farwell. The interpretation of the US and British agencies appear to be different.
It is a long thread, so the link I give below is where the first response from the USCG occurs. There follows a lot of comments from particular one member of the chattering class, but there are knowledgeable sailors and professionals who also make good comments. Mods, I hope it is not inappropriate to link to another forum, as I did check the rules here and I could not find anything that said otherwise.
It may be interesting from those who are professional Mariners, to see the discussion and possibly have their input into it.